The small tractor provided with a mechanical attachment such as a mower and used exclusively for mowing lawn has been known from the past.
Examples of such tractors as above are shown in FIGS. 13, 14, and 15 of the attached drawings.
For these small tractors, it is necessary to transmit driving power from the engine to both the driving power transmission unit and the mower, the purpose being fulfilled by a structure composed of two systems. Accordingly, V-belts and V-pulleys are arranged in double steps under the tractor body while occupying a space for driving power transmission units and depriving the mower of space for lifting and lowering, thereby making the power transmission mechanism complicated.
The prior art disclosed in the U.S. Pat. No. 3,766,722, which is similar to the above-described art, is exemplary of such prior art tractors.